Problem: The lifespans of seals in a particular zoo are normally distributed. The average seal lives $13.8$ years; the standard deviation is $3.2$ years. Use the empirical rule $(68-95-99.7\%)$ to estimate the probability of a seal living less than $7.4$ years.
Solution: The probability of a particular seal living less than $7.4$ years is ${2.5\%}$.